| 摘要 |
PURPOSE:To halve the current consumption of step motor, by automatically changing the drive current in response to the load, through the drive current control function given to the step motor mechanism. CONSTITUTION:Constitution is made to play the drive current control function by operating the load detection mechanism and the control circuit. When the input in1 of the NAND gate 11 is H, the drive current flows and the rotor turns. Accompanied with the revolution of the rotor, the detection voltage is induced in the detection coil 6. This voltage is fed to the gate of the inverter 8 via the differentiation circuit. When the rotor turns by a given angle and the voltage of the coil 6 is small, the gate voltage of the inverter 8 is lowered than the threshold voltage with the operation of the differentiation circuit, the inverter 8 is inverted into H. Then, the output of the inverter 10 is inverted into L, then the both outputs of the gate 11 are H to interrupt the drive current. Thus, the time signal starts flowing the drive current and the drive current is interrupted with specified revolution of the rotor, allowing remarkable reduction in the current consumption. |
